RESEARCH


“For years, people said you needed to teach deaf children differently, but the point is children will respond to spoken language when you teach the brain by giving them hearing.” --Doreen Pollack, early pioneer of the Auditory Verbal approach, spoken years before much of the research about the brain, and before the advent of cochlear implants!

We provide these abstracts for your information. Please remember that abstracts, while helpful, are not as complete as the full text. Also, we have focused primarily on research regarding children; there is also a lot out there about adult implantees. The easiest place to read these studies is on PubMed:
http://www.ncbi.nlm.nih.gov/sites/entrez?db=PubMed. We encourage you to research, ask questions and be your own best advocate!


Early Implantation

J Neurophysiol. 2007 Sep 12; [Epub ahead of print]

Spatial Selectivity to Intracochlear Electrical Stimulation in the Inferior Colliculus is Degraded Following Long-Term Deafness in Cats.
Vollmer M, Beitel RE, Snyder RL, Leake PA.
Otolaryngology, University Hospital Wuerzburg, Wuerzburg, Germany; Otolaryngology, University of California, San Francisco, 513 Parnassus Ave., San Francisco, California, 94143-0526, United States.
In an animal model of electrical hearing in prelingually deaf adults this study examined the effects of deafness duration on response thresholds and spatial selectivity (i.e., cochleotopic organization, spatial tuning and dynamic range) in the central auditory system to intracochlear electrical stimulation. Electrically evoked auditory brainstem response (EABR) thresholds and neural response thresholds in the external (ICX) and central (ICC) nuclei of the inferior colliculus were estimated in cats after varying durations of neonatally induced deafness: 1) in animals deafened <1.5 yr (short-deafened unstimulated, SDU cats) with a mean spiral ganglion cell (SGC) density of ~45% of normal and 2) in animals deafened >2.5 yr (long-deafened, LD cats) with severe cochlear pathology (mean SGC density <7% of normal). LD animals were subdivided into unstimulated cats and those that received chronic intracochlear electrical stimulation via a feline cochlear implant. Acutely deafened, implanted adult cats served as controls. Independent of their stimulation history, LD animals had significantly higher EABR and ICC thresholds than SDU and control animals. Moreover, the spread of electrical excitation was significantly broader and the dynamic range significantly reduced in LD animals. Despite the prolonged durations of deafness the fundamental cochleotopic organization was maintained in both the ICX and the ICC of LD animals. There was no difference between SDU and control cats in any of the response properties tested. These findings suggest that long-term auditory deprivation results in a significant and possibly irreversible degradation of response thresholds and spatial selectivity to intracochlear electrical stimulation in the auditory midbrain.

Int J Pediatr Otorhinolaryngol. 2007 Sep 13; [Epub ahead of print]

Pediatric cochlear implantation in Taiwan: Long-term communication outcomes.
Wang NM, Huang TS, Wu CM, Kirk KI.
Department of Speech Language Pathology & Audiology, Chung Shan Medical University, No. 110 Chien Kuo North Road, Section 1, Taichung 402, Taiwan.
OBJECTIVES/HYPOTHESIS: Cochlear implantation is an established method of auditory rehabilitation for severely and profoundly hearing impaired individuals. Although numerous studies have examined communication outcomes in pediatric cochlear implant (CI) recipients, data concerning the benefits of cochlear implantation in children who speak Mandarin Chinese are lacking. This study examined communication outcomes in 29 Mandarin-speaking children implanted at Chung Gung Memorial Hospital. DESIGN: A prospective between-groups design was used to compare communication outcomes as a function of age at time of implantation. METHODS: Children in the Younger group were implanted before 3 years of age, whereas children in the Older group were implanted after 3 years of age. Outcome measures assessed auditory thresholds, speech perception, speech intelligibility, receptive and expressive language skills, communication barriers, and communication mode. Correlation analysis was used to examine the relationship between communication outcome and age at implantation. RESULTS: Children in the Younger group demonstrated a significant level of difference on Mandarin vowels, consonants, tones, and open-set speech perception compared with the children in the Older group. Between-group differences were also shown on receptive and expressive language skills. But, no significant differences were noted on speech intelligibility or in self-ratings of communication barriers. A larger proportion of children in the Younger group used oral communication and were educated in mainstream classrooms. Communication mode change of the Younger group reached a significant level after cochlear implant. Speech perception performance was negatively correlated with age at implantation as well as chronological age. Mandarin-speaking children can obtain substantial communication benefits from cochlear implantation, with earlier implantation yielding superior results.
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No To Hattatsu. 2007 Sep;39(5):335-45

[Development of hearing, speech and language in congenitally deaf infants and children after cochlear implantation]
Department of Otolaryngology, Head & Neck Surgery, Graduate School of Medicine, University of Tokyo, Tokyo.
In Japan, universal newborn hearing screening has been partly introduced since 2000 in order to discover neonates with congenital deafness, and the average age at discovery was around five months; however, among infants who were not examined by the universal newborn hearing screening, the average age at discovery was around two years. After fitting hearing aids, congenitally deaf infants are educated in a preschool for speech and hearing. If hearing aids are not effective to develop hearing and speech, cochlear implant surgery is performed as modern technology. The outcome of hearing, speech and language after cochlear implantation was excellent. At the age of elementary school enrollment, most of their verbal IQ was considered to be the same as age-matched normal children. Cochlear implant is the most important treatment at present.
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Int J Pediatr Otorhinolaryngol. 2007 Aug 9; [Epub ahead of print]Click here to read Links
Deaf children with cochlear implants before the age of 1 year: Comparison of preverbal communication with normally hearing children.
Tait M, De Raeve L, Nikolopoulos TP.

The Ear Foundation, Nottingham, United Kingdom.

OBJECTIVES: To compare preverbal behaviors of deaf children implanted under 1 year of age with age-matched hearing children. METHODS: The study assessed 20 children; 10 deaf children implanted under 1 year of age and 10 normally hearing children of the same age. Preverbal skills were measured before, 6 months, and 1 year after implantation, using Tait Video Analysis that is able to predict later speech outcomes in young implanted children. RESULTS: Regarding vocal turns, the normally hearing group outperformed the implanted group although the latter children became quite vocal, nearly 60% of their turns being taken in this way. The mean vocal autonomy in implanted children, 1 year after implantation, was very close to the respective of hearing children (38.5 versus 43.5). Regarding the non-looking vocal turns, by the 12-month interval, hearing children had somewhat higher scores than implanted children, but the difference was not significant and the increase in implanted children was much higher (40-fold increase versus 4-fold increase). However, implanted children were more likely to use silent communication than hearing children, although gestural turns were decreasing with time. CONCLUSIONS: The small numbers in this study, although two of the largest European cochlear implant centers were combined to recruit such young implantees, led us to be cautious in interpreting the results. However, it seems that in deaf implanted children under 1 year of age, some preverbal communication behaviors are developing to an extent (although at a somewhat lower level) not significantly different from those of age-matched normally hearing children.
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J Speech Lang Hear Res. 2007 Aug;50(4):1048-62.Click here to read Links
Will they catch up? The role of age at cochlear implantation in the spoken language development of children with severe to profound hearing loss.
Nicholas JG, Geers AE.

Central Institute for the Deaf at Washington University School of Medicine, Department of Otolaryngology, Box 8115, 660 South Euclid Avenue, St. Louis, Missouri 63110, USA. nicholasj@ent.wustl.edu

PURPOSE: The authors examined the benefits of younger cochlear implantation, longer cochlear implant use, and greater pre-implant aided hearing to spoken language at 3.5 and 4.5 years of age. METHOD: Language samples were obtained at ages 3.5 and 4.5 years from 76 children who received an implant by their 3rd birthday. Hierarchical linear modeling was used to identify characteristics associated with spoken language outcomes at the 2 test ages. The Preschool Language Scale (I. L. Zimmerman, V. G. Steiner, & R. E. Pond, 1992) was used to compare the participants' skills with those of hearing age-mates at age 4.5 years. RESULTS: Expected language scores increased with younger age at implant and lower pre-implant thresholds, even when compared at the same duration of implant use. Expected Preschool Language Scale scores of the children who received the implant at the youngest ages reached those of hearing age-mates by 4.5 years, but those children implanted after 24 months of age did not catch up with hearing peers. CONCLUSION: Children who received a cochlear implant before a substantial delay in spoken language developed (i.e., between 12 and 16 months) were more likely to achieve age-appropriate spoken language. These results favor cochlear implantation before 24 months of age, especially for children with aided pure-tone average thresholds greater than 65 dB prior to surgery.
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Ear Hear. 2007 Apr;28(2 Suppl):56S-58S.Click here to read Links
Age and outcome of cochlear implantation for patients with bilateral congenital deafness in a Cantonese-speaking population.
Tong MC, Leung EK, Au A, Lee W, Yue V, Lee KY, Chan VS, Wong TK, Cheung DM, van Hasselt CA.

The Chinese University of Hong Kong, Hong Kong, China. mtong@surgery.cuhk.edu.hk

OBJECTIVE: To evaluate the effect of age at implantation by assessment of speech perception in cochlear implant users with bilateral congenital deafness. DESIGN: A retrospective cohort analysis of 60 cochlear implant users (age at implantation, 1.01 to 22.0 yr) who have at least 2 yr of experience. Their outcome performance was defined by the change in i) speech perception category (SPC) score based on postoperative assessment results and ii) the type of education attended after implantation. The association of age at implantation with SPC scores was analyzed at different ages at implantation (2, 3, 4, 5, and 6 yr old). The SPC scores for a particular age at implantation were compared at 6, 12, and 24 mo after implantation. The impact of age at implantation on choice of education was evaluated by analyzing the transition from a school for the deaf to mainstream education for the 45 children who were operated on before the age of 10, because older children are less likely to make such a change. RESULTS: Children implanted at the ages of 2, 3, 4, 5, and 6 yr all obtained significant improvements in SPC scores 24 mo after implantation. The greatest improvement was noted at 24 mo after implantation among those operated on before age 3. For all age groups, improvement at 24 mo after implantation is greater than at 12 mo, whereas the latter is greater than the improvement noted at 6 mo after implantation. Comparison of children implanted before the age of 3 and between ages 3 and 10 showed a significant difference in the choice of education after implantation. Children who were implanted before the age of 3 were more likely to attend mainstream education after implantation. CONCLUSION: Results from the present study are consistent with the current belief that implantation at a younger age provides greater benefit. The proportion of children attending mainstream education was significantly higher for those implanted before age 3, which may be a potential benefit to early implantation for relieving the burden of governments in providing special education.
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Int J Pediatr Otorhinolaryngol. 2007 Apr;71(4):603-10. Epub 2007 Jan 18.Click here to read Links
Age at implantation and development of vocal and auditory preverbal skills in implanted deaf children.
Tait ME, Nikolopoulos TP, Lutman ME.

The Ear Foundation, Nottingham, United Kingdom.

BACKGROUND: Preverbal vocal and auditory skills are essential precursors of spoken language development and they have been shown previously to predict later speech perception and production outcomes in young implanted deaf children. OBJECTIVES: To assess the effect of age at implantation on the development of vocal and auditory preverbal skills in implanted children. METHODS: The study assessed 99 children, 33 in each of three groups (those implanted between 1 and 2 years; 2 and 3 years; and 3 and 4 years). Preverbal skills were measured in three areas: turn taking, autonomy and auditory awareness of spoken language, using the Tait video analysis method. RESULTS: The youngest implanted group made an exceptional progress outperforming in all measures the two other groups (p<0.01), 6 and 12 months post-implantation, whereas there was no such difference before implantation. In the youngest group there was also significantly greater use of an auditory/oral style of communication: 85% of the group by 12 months post-implantation compared with 30% and 18% of the two older groups. CONCLUSIONS: Vocal and auditory preverbal skills develop much more rapidly in children implanted between 1 and 2 years in comparison with older implanted children and reach a significantly higher level by 6 and 12 months post-implantation. In addition, younger implanted children are significantly more likely by 12 months post-implantation to adopt an auditory/oral mode of communication. These findings favour cochlear implantation as early as between 1 and 2 years, provided that correct diagnosis and adequate hearing-aid trial have been achieved.
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Prog Brain Res. 2006;157:283-313.Links
Cochlear implants: cortical plasticity in congenital deprivation.
Kral A, Tillein J, Heid S, Klinke R, Hartmann R.

Laboratories of Auditory Neuroscience, Institute of Neurophysiology and Pathophysiology, University of Hamburg School of Medicine, Hamburg, Germany. a.kral@uke.uni-hamburg.de

Congenital auditory deprivation (deafness) leads to a dysfunctional intrinsic cortical microcircuitry. This chapter reviews these deficits with a particular emphasis on layer-specific activity within the primary auditory cortex. Evidence for a delay in activation of supragranular layers and reduction in activity in infragranular layers is discussed. Such deficits indicate the incompetence of the primary auditory cortex to not only properly process thalamic input and generate output within the infragranular layers, but also incorporate top-down modulations from higher order auditory cortex into the processing within primary auditory cortex. Such deficits are the consequence of a misguided postnatal development. Maturation of primary auditory cortex in deaf animals shows evidence of a developmental delay and further alterations in gross synaptic currents, spread of activation, and morphology of local field potentials recorded at the cortical surface. Additionally, degenerative changes can be observed. When hearing is initiated early in life (e.g., by chronic cochlear-implant stimulation), many of these deficits are counterbalanced. However, plasticity of the auditory cortex decreases with increasing age, so that a sensitive period for plastic adaptation can be demonstrated within the second to sixth months of life in the deaf cat. Potential molecular mechanisms of the existence of sensitive period are discussed. Data from animal research may be compared to electroencephalographic data obtained from cochlear-implanted congenitally deaf children. After cochlear implantation in humans, three phases of plastic adaptation can be observed: a fast one, taking place within the first few weeks after implantation, showing no sensitive period; a slower one, taking place within the first months after implantation (a sensitive period up to 4 years of age); and possibly a third, and the longest one, related to increasing activation of higher order cortical areas.
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Ear Hear. 2006 Dec;27(6):628-44.Click here to read Links
The age at which young deaf children receive cochlear implants and their vocabulary and speech-production growth: is there an added value for early implantation?
Connor CM, Craig HK, Raudenbush SW, Heavner K, Zwolan TA.

Florida State University and the Florida Center for Reading Research, Tallahassee, FL 32301, USA. cconnor@fcrr.org

OBJECTIVE: The age at which a child receives a cochlear implant seems to be one of the more important predictors of his or her speech and language outcomes. However, understanding the association between age at implantation and child outcomes is complex because a child's age, length of device use, and age at implantation are highly related. In this study, we investigate whether there is an added value to earlier implantation or whether advantages observed in child outcomes are primarily attributable to longer device use at any given age. DESIGN: Using hierarchical linear modeling, we examined latent-growth curves for 100 children who had received their implants when they were between 1 and 10 yr of age, had used oral communication, and had used their devices for between 1 and 12 yr. Children were divided into four groups based on age at implantation: between 1 and 2.5 yr, between 2.6 and 3.5 yr, between 3.6 and 7 yr, and between 7.1 and 10 yr. RESULTS: Investigation of growth curves and rates of growth over time revealed an additional value for earlier implantation over and above advantages attributable to longer length of use at any given age. Children who had received their implants before the age of 2.5 yr had exhibited early bursts of growth in consonant-production accuracy and vocabulary and also had significantly stronger outcomes compared with age peers who had received their implants at later ages. The magnitude of the early burst diminished systematically with increasing age at implantation and was not observed for children who were older than 7 yr at implantation for consonant-production accuracy or for children who were over 3.5 yr old at implantation for vocabulary. The impact of age at implantation on children's growth curves differed for speech production and vocabulary. CONCLUSIONS: There seems to be a substantial benefit for both speech and vocabulary outcomes when children receive their implant before the age of 2.5 yr. This benefit may combine a burst of growth after implantation with the impact of increased length of use at any given age. The added advantage (i.e., burst of growth) diminishes systematically with increasing age at implantation.
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Pediatrics. 2006 Oct;118(4):1350-6.Click here to read Links
Does cause of deafness influence outcome after cochlear implantation in children?
Nikolopoulos TP, Archbold SM, O'Donoghue GM.

Department of Otorhinolaryngology, Athens University, Hippokration Hospital, Athens, Greece. thomas.nikolopoulos@nottingham.ac.uk

OBJECTIVES: The objective of this study was to evaluate long-term speech perception abilities of comparable groups of postmeningitic and congenitally deaf children after cochlear implantation. METHODS: This prospective longitudinal study comprised 46 postmeningitic deaf children and 83 congenitally deaf children with age at implantation of < or = 5.6 years. Both groups were comparable with respect to educational setting and mode of communication and included children with additional disabilities. RESULTS: Both postmeningitic and congenitally deaf children showed significant progress after implantation. Most (73% and 77%, respectively) could understand conversation without lip-reading or use the telephone with a known speaker 5 years after implantation, whereas none could do so before implantation. At the same interval, the postmeningitic and congenitally deaf children scored a mean open-set speech perception score of 47 (range: 0-91) and 46 (range: 0-107) words per minute, respectively, on connected discourse tracking. The respective mean scores at the 3-year interval were 22 and 29 correct words per minute, respectively. None of these children could score a single correct word per minute before implantation. The progress in both groups was statistically significant. When the 2 groups were compared, there was no statistically significant difference. CONCLUSION: Postmeningitic and congenitally deaf children showed significant improvement in their auditory receptive abilities at the 3- and 5-year intervals after cochlear implantation. There was no statistically significant difference between the outcomes of the 2 groups, suggesting that, provided that children receive an implant early, cause of deafness has little influence on outcome. Although the prevalence of other disabilities was similar in both groups, for individual children, their presence may have profound impact. The study supports the concept of implantation early in life, irrespective of the cause of deafness.
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J Speech Lang Hear Res. 2007 Apr;50(2):393-407.Click here to read Links
Profiles of vocal development in young cochlear implant recipients.
Ertmer DJ, Young NM, Nathani S.

Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, IN 47907, USA. dertmer@purdue.edu

PURPOSE: The main purpose of this investigation was to examine the effects of cochlear implant experience on prelinguistic vocal development in young deaf children. Procedure A prospective longitudinal research design was used to document the sequence and time course of vocal development in 7 children who were implanted between 10 and 36 months of age. Speech samples were collected twice before implant activation and on a monthly basis thereafter for up to 2 years. Children's vocalizations were classified according to the levels of the Stark Assessment of Early Vocal Development--Revised (SAEVD-R; S. Nathani, D. J Ertmer, & R. E. Stark, 2006). RESULTS: The main findings were (a) 6 of 7 children made advancements in vocal development after implantation; (b) children implanted between 12 and 36 months progressed through SAEVD-R levels in the predicted sequence, whereas a child implanted at a younger age showed a different sequence; (c) milestones in vocal development were often achieved with fewer months of hearing experience than observed in typically developing infants and appeared to be influenced by age at implantation; and (d) in general, children implanted at younger ages completed vocal development at younger chronological ages than those implanted later in life. Specific indicators of benefit from implant use were also identified. CONCLUSION: The time course of vocal development in young cochlear implant recipients can provide clinically useful information for assessing the benefits of implant experience. Studies of postimplantation vocal development have the potential to inform theories of spoken language development.
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Ear Hear. 2006 Jun;27(3):286-98.Click here to read Links
Effects of early auditory experience on the spoken language of deaf children at 3 years of age.
Nicholas JG, Geers AE.

Central Institute for the Deaf Research, Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri 63110, USA. NicholasJ@ent.wustl.edu

OBJECTIVE: By age 3, typically developing children have achieved extensive vocabulary and syntax skills that facilitate both cognitive and social development. Substantial delays in spoken language acquisition have been documented for children with severe to profound deafness, even those with auditory oral training and early hearing aid use. This study documents the spoken language skills achieved by orally educated 3-yr-olds whose profound hearing loss was identified and hearing aids fitted between 1 and 30 mo of age and who received a cochlear implant between 12 and 38 mo of age. The purpose of the analysis was to examine the effects of age, duration, and type of early auditory experience on spoken language competence at age 3.5 yr. DESIGN: The spoken language skills of 76 children who had used a cochlear implant for at least 7 mo were evaluated via standardized 30-minute language sample analysis, a parent-completed vocabulary checklist, and a teacher language-rating scale. The children were recruited from and enrolled in oral education programs or therapy practices across the United States. Inclusion criteria included presumed deaf since birth, English the primary language of the home, no other known conditions that interfere with speech/language development, enrolled in programs using oral education methods, and no known problems with the cochlear implant lasting more than 30 days. RESULTS: Strong correlations were obtained among all language measures. Therefore, principal components analysis was used to derive a single Language Factor score for each child. A number of possible predictors of language outcome were examined, including age at identification and intervention with a hearing aid, duration of use of a hearing aid, pre-implant pure-tone average (PTA) threshold with a hearing aid, PTA threshold with a cochlear implant, and duration of use of a cochlear implant/age at implantation (the last two variables were practically identical because all children were tested between 40 and 44 mo of age). Examination of the independent influence of these predictors through multiple regression analysis revealed that pre-implant-aided PTA threshold and duration of cochlear implant use (i.e., age at implant) accounted for 58% of the variance in Language Factor scores. A significant negative coefficient associated with pre-implant-aided threshold indicated that children with poorer hearing before implantation exhibited poorer language skills at age 3.5 yr. Likewise, a strong positive coefficient associated with duration of implant use indicated that children who had used their implant for a longer period of time (i.e., who were implanted at an earlier age) exhibited better language at age 3.5 yr. Age at identification and amplification was unrelated to language outcome, as was aided threshold with the cochlear implant. A significant quadratic trend in the relation between duration of implant use and language score revealed a steady increase in language skill (at age 3.5 yr) for each additional month of use of a cochlear implant after the first 12 mo of implant use. The advantage to language of longer implant use became more pronounced over time. CONCLUSIONS: Longer use of a cochlear implant in infancy and very early childhood dramatically affects the amount of spoken language exhibited by 3-yr-old, profoundly deaf children. In this sample, the amount of pre-implant intervention with a hearing aid was not related to language outcome at 3.5 yr of age. Rather, it was cochlear implantation at a younger age that served to promote spoken language competence. The previously identified language-facilitating factors of early identification of hearing impairment and early educational intervention may not be sufficient for optimizing spoken language of profoundly deaf children unless it leads to early cochlear implantation.
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Pediatrics. 2005 Oct;116(4):e487-93.Click here to read Links
Cochlear implantation in children younger than 12 months.
Waltzman SB, Roland JT Jr.

Department of Otolaryngology, New York University School of Medicine, New York, New York, USA. susan.waltzman@med.nyu.edu

OBJECTIVES: As a result of universal newborn hearing screening and improved evaluation tools, many children with severe to profound hearing loss are being diagnosed as infants. This affords the opportunity to provide these children access to cochlear implantation, although medical and audiologic challenges must be addressed. The purpose of this study was to investigate the safety and efficacy of cochlear implantation in children who are younger than 1 year. METHODS: A prospective study was conducted of 18 children who had confirmed severe to profound sensorineural hearing loss and received cochlear implants at our medical center before 12 months of age. The length of device usage ranged from 6 months to 4 years, 5 months. The main outcomes measured were perioperative and postoperative surgical/medical aspects, the Infant-Toddler Meaningful Auditory Integration Scale and age-appropriate phoneme, and word and sentence recognition tests, when appropriate. RESULTS: All children had full insertions of the electrode array without surgical complications and are developing age-appropriate auditory perception and oral language skills. CONCLUSIONS: Early implantation is feasible and beneficial in some children who are younger than 12 months and should be considered with attention to variables involved in the decision-making process, including possible increased surgical risk, skull size and scalp thickness, and mastoid development.
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Laryngoscope. 2005 Aug;115(8):1376-80.Click here to read Links
Cochlear implantation in deaf infants.
Miyamoto RT, Houston DM, Bergeson T.

Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine, 699 West Drive, Indianapolis, IN 46202, U.S.A.

OBJECTIVES: With the application of universal newborn hearing screening programs, a large pool of newly identified deaf infants has been identified. The benefits of early intervention with cochlear implants (CI) is being explored. Mounting evidence suggests that age at implantation is a strong predictor of language outcomes. However, new behavioral procedures are needed to measure speech and language skills during infancy. Also, procedures are needed to analyze the speech input to young CI recipients. STUDY DESIGN: Cohort-sequential. METHODS: Thirteen infants with profound hearing loss who were implanted between the ages of 6 to 12 months of age participated in this study. Eight participated in two new behavioral methodologies: 1) the visual habituation procedure to assess their discrimination of speech sounds; 2) the preferential looking paradigm to assess their ability to learn associations between speech sounds and objects. Older implanted infants and normal-hearing infants were also tested for comparison. The pitch of mothers' speech to infants was analyzed. RESULTS: Patterns of looking times for the very early implanted infants were similar to those of normal hearing infants. Mothers' speech to infants with CIs was similar in pitch to normal-hearing infants who had the same duration of experience with sounds. CONCLUSIONS: No surgical or anesthetic complications occurred in this group of infants, and the pattern of listening skill development mirrors that seen in normal-hearing infants. Mothers adjust their speech to suit the listening experience of their infants.
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Laryngoscope. 2005 Mar;115(3):445-9.Click here to read Links
Cochlear implantation at under 12 months: report on 10 patients.
Colletti V, Carner M, Miorelli V, Guida M, Colletti L, Fiorino FG.

ENT Department, University of Verona, Verona, Italy. vittoricolletti@yahoo.com

OBJECTIVES: There is growing evidence that early application of a cochlear implant in children affected by profound congenital hearing loss is of paramount importance for the development of an adequate auditory performance and language skills. For these reasons and as a result of advances in audiologic diagnosis and an enhanced awareness of the safety of cochlear implants, the age of implantation has substantially decreased over recent years. Children aged as little as 12 months are now being implanted in some centers. On the basis of our experience with very young children, we believe that the date of implantation may be further reduced to only 4 to 6 months of age. STUDY DESIGN: Over the period from November 1998 to April 2004, 103 children have been fitted with cochlear implants and 11 with auditory brainstem implants in our department, including 65 children aged below 3 years. The present study focuses on 10 children aged less than 12 months fitted with cochlear implants from November 1998 to December 2003. METHODS: The children's ages ranged from 4 to 11 (mean 9.5) months. Five were males and five females. All received a Nucleus CI 24 M. Postoperative auditory performance, as evaluated at the latest follow-up, was based on the category of auditory performance (CAP). The results obtained in these 10 children were compared with those obtained with cochlear implants in children belonging to older age brackets. The criteria used to assess speech performance were onset of babbling onset and babbling spurt, and the results observed were compared with those of a control group of 10 normally hearing children. RESULTS: Surgery was uneventful, and no immediate or delayed complications were encountered. Auditory performance was seen to increase as function of early age of implantation and length of implant use. All 10 children had a CAP score of 3 within 6 months of cochlear implant activation. The onset of babbling occurred very early (i.e., within 1 to 3 months of activation of the implant in all 10 patients), regardless of age at implantation, whereas the babbling spurt was recorded at times ranging from 3 to 5 months after implant activation. The positive impact of early implantation on babbling was clearly shown by the fact that the earlier the activation of the cochlear implant, the closer the results were to the outcomes of normally hearing children. CONCLUSIONS: We encourage very early implantation to facilitate a series of developmental processes occurring in the critical period of initial language acquisition. The indices we used in the present study (i.e., CAP and babbling) suggest that early cochlear implantation tends to yield normalization of audio-phonologic parameters, which enables us to consider the performance of children implanted very early as being similar to that of their normally hearing peers.





Auditory Verbal Therapy
(Remember, AVT can often be supported by research regarding the more general term of "oral education," although it is a subset of that)

Research outcomes of auditory-verbal intervention: Is the approach justified?
Deafness & Education International
Volume 8, Issue 3, Date: September 2006, Pages: 125-143
Ellen A. Rhoades

(research below comes directly from AVI and A. G. Bell)




      Oral Education/Methodology

      Arch Otolaryngol Head Neck Surg. 2004 May;130(5):639-43.Click here to read Links
      Mode of communication and classroom placement impact on speech intelligibility.
      Tobey EA, Rekart D, Buckley K, Geers AE.

      Callier Advanced Hearing Research Center, University of Texas at Dallas, 75235, USA. Etobey@utdallas.edu

      OBJECTIVE: To examine the impact of classroom placement and mode of communication on speech intelligibility scores in children aged 8 to 9 years using multichannel cochlear implants. DESIGN: Classroom placement (special education, partial mainstream, and full mainstream) and mode of communication (total communication and auditory-oral) reported via parental rating scales before and 4 times after implantation were the independent variables. Speech intelligibility scores obtained at 8 to 9 years of age were the dependent variables. PARTICIPANTS: The study included 131 congenitally deafened children between the ages of 8 and 9 years who received a multichannel cochlear implant before the age of 5 years. RESULTS: Higher speech intelligibility scores at 8 to 9 years of age were significantly associated with enrollment in auditory-oral programs rather than enrollment in total communication programs, regardless of when the mode of communication was used (before or after implantation). Speech intelligibility at 8 to 9 years of age was not significantly influenced by classroom placement before implantation, regardless of mode of communication. After implantation, however, there were significant associations between classroom placement and speech intelligibility scores at 8 to 9 years of age. Higher speech intelligibility scores at 8 to 9 years of age were associated with classroom exposure to normal-hearing peers in full or partial mainstream placements than in self-contained, special education placements. CONCLUSIONS: Higher speech intelligibility scores in 8- to 9-year-old congenitally deafened cochlear implant recipients were associated with educational settings that emphasize oral communication development. Educational environments that incorporate exposure to normal-hearing peers were also associated with higher speech intelligibility scores at 8 to 9 years of age.
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      Ear Hear. 2003 Feb;24(1 Suppl):90S-105S.Click here to read Links
      Acoustic characteristics of the speech of young cochlear implant users: a comparison with normal-hearing age-mates.
      Uchanski RM, Geers AE.

      Central Institute for the Deaf, St Louis, Missouri 63110, USA. ruchanski@cid.wustl.edu

      OBJECTIVE: The primary objective of this study was to compare select acoustic characteristics of the speech of deaf children who use cochlear implants (young cochlear implant users) with those of children with normal hearing. A secondary objective of this study was to examine the effect, if any, of the deaf child's education (oral versus total communication) on the similarity of these acoustic characteristics to those of normal-hearing age-mates. DESIGN: Speech was recorded from 181 young cochlear implant users and from 24 children with normal hearing. All speech was produced by imitation, and consisted of complete sentences. Acoustic measures included voice onset time (/t/, /d/), second formant frequency (/i/, /[U0254]/), spectral moments (mean, skew and kurtosis of /s/ and /[U0283]/), a nasal manner metric, and durations (of vowels, words, and sentences). RESULTS AND DISCUSSION: A large percentage (46 to 97%) of the young cochlear implant users produced acoustic characteristics with values within the range found for children with normal hearing. Exceptions were sentence duration and vowel duration in sentence-initial words, for which only 23 and 25%, respectively, of the COCHLEAR IMPLANT users had values within the normal range. Additionally, for most of the acoustic measures, significantly more COCHLEAR IMPLANT users from oral than from total communication settings had values within the normal range. CONCLUSIONS: Compared with deaf children with hearing aids (from previous studies by others), deaf children who use cochlear implants have improved speech production skills, as reflected in the acoustic measures of this study. Placement in an oral communication educational setting is also associated with more speech production improvement than placement in a total communication setting.
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      Ann Otol Rhinol Laryngol Suppl. 2002 May;189:138-42.Links
      Changing expectations for children with cochlear implants.
      Moog JS.

      Moog Center for Deaf Education, St Louis, Missouri 63141, USA.

      Seventeen students with cochlear implants who were between 5 and 11 years of age and attended the Moog Center for Deaf Education school program were tested just before exiting the program. The Moog program is an intensive oral program that provides very focused instruction in spoken language and reading. Children leave the program when they are ready for a mainstream setting or when they are 11 years of age, whichever comes first. All of the children demonstrated open-set speech perception ranging from 36% to 100%. On a test of speech intelligibility, all students scored 90% or better. On language and reading tests, compared with the performance of normal-hearing children their age, more than 65% scored within the average range for language and more than 70% scored within the average range for reading. These data demonstrate what is possible for deaf children who benefit from a combination of a cochlear implant and a highly focused oral education program.





      Efficacy/Benefit of Cochlear implants

      Int J Pediatr Otorhinolaryngol. 2005 Dec;69(12):1675-83. Epub 2005 Jun 13.Click here to read Links
      Speech perception of children using Nucleus, Clarion or Med-El cochlear implants.
      Taitelbaum-Swead R, Kishon-Rabin L, Kaplan-Neeman R, Muchnik C, Kronenberg J, Hildesheimer M.

      Department of Communication Disorders, Sackler Faculty of Medicine, Tel-Aviv University, Israel. taite@post.tau.ac.il

      OBJECTIVE: The purpose of this study was to present speech perception achievements of implanted children using commercially available cochlear implant devices: Nucleus, Clarion or Med-El. STUDY DESIGN: A retrospective analysis. METHODS: Speech perception data of 96 hearing-impaired children: 27 with Clarion, 49 with Nucleus and 20 with Med-El were collected. Speech tests included the Hebrew Infant Toddlers Meaningful Auditory Integration Scale (HIT-MAIS) for the infants, the Hebrew Early Speech Perception (HESP) closed-set word-identification test and Hebrew Arthur Boothroyd (HAB) open-set one-syllable word recognition test were used for the older children. RESULTS: I HIT-MAIS: (1) Infants showed similar rate of progress, regardless of device. (2) Children implanted under two years of age reached performance within normal development on this test. II HAB: (1) Most children achieved open set results with mean HAB between 40 and 50%, within 1-1.5 years post implantation. (2) Linear regression analyses revealed no statistical differences between the Clarion the Nucleus and the Med-El devices on the mean final measurement of this test. (3) Age of implantation and mode of communication were significant covariate variables: (a) the younger the child is implanted the better the results and (b) oral communication prior to implantation results in better performance than sign language. CONCLUSIONS: There are no apparent differences in speech perception performance between implant devices when considering background variables. The data have important implications on the rehabilitation process of hearing impaired children with cochlear implants in relation to device selection, age at implantation and mode of communication prior to implantation.
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      Curr Opin Otolaryngol Head Neck Surg. 2006 Oct;14(5):337-40.Click here to read Links
      Cochlear implant-mediated perception of music.
      Limb CJ.

      Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Hospital, Baltimore, Maryland 21287, USA. climb@jhmi.edu

      PURPOSE OF REVIEW: This paper examines and consolidates recent advances in cochlear implant sound processing from the perspective of music perception, which is increasingly viewed as one of the most difficult of all listening conditions. RECENT FINDINGS: Music is an essentially abstract, complex form of sound composed of multiple layers of sounds that vary in temporal presentation, frequency distribution, and harmonic content. As a result, music perception is perhaps the most challenging aspect of implant-mediated listening. Thus far, implant performance has shown poor performance overall during perception of musical pitches, melodies, and timbre while perception of rhythm is relatively good. Recent advances in implant sound processing strategies, particularly the use of current distribution along adjacent electrodes, have promising early results in terms of improving the number of pitch percepts available to cochlear implant listeners. SUMMARY: Music perception poses auditory challenges that can exceed those of language perception during cochlear implant-mediated listening. These challenges should be emphasized to patients prior to implantation. Although rhythm perception via cochlear implants is reasonably good using simple test paradigms, significant work remains to improve critically important aspects of music perception, including melody and timbre. New implant processing strategies are encouraging and should lead to improved music perception in the near future.
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      Laryngoscope. 2007 Jun 20; [Epub ahead of print]Click here to read Links
      A Comparison of Postcochlear Implantation Speech Scores in an Adult Population.
      Bodmer D, Shipp DB, Ostroff JM, Ng AH, Stewart S, Chen JM, Nedzelski JM.

      From the Department of Otolaryngology–Head and Neck Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.

      OBJECTIVES:: The vast majority of cochlear implant recipients realize significant improvement in speech perception. However, there continue to be a small group that does not realize such a benefit. In an effort to identify possible predictors for this, we have compared pre- and postimplant audiologic data using Hearing In Noise Test (HINT), City University of New York (CUNY), or Central Institute for the Deaf (CID) scores for 445 consecutive English-speaking adult patients followed for a minimum of 1 year postimplantation in two distinct groups, poor versus excellent performers. STUDY DESIGN:: Retrospective. METHODS:: Poor performers were those who realized a worsening, no improvement, or an improvement of less than 10%. This group numbered 58 (13%). High performers consisted of a cadre of 194 (44%) patients who scored between 91 and 100% postimplantation. Demographic data relating to onset of deafness, education exposure, etiology, etc., were evaluated. RESULTS:: Of the poor performers, 33 (57%) were pre-/perilingually deafened. Of these, 79% had not received any auditory/oral training in childhood. On the other hand, a total of 109 implant recipients were individuals who were pre-/perilingually deafened. Of these, 24 were in the excellent performer category. All were identified early and were recipients of a strong auditory/oral education. Of the high performers, 170 (88%) were deafened late. Other findings such as preoperative electronystagmography with caloric testing, hearing aid use, device type, and high-resolution computed tomography scan of the temporal bone will be discussed for both groups. CONCLUSIONS:: A high preimplant speech score, auditory verbal therapy, and postlingual deafness statistically correlate with higher postimplant speech scores 1 year after cochlear implantation. Device type, caloric response and hearing aid use preimplantation, age at surgery, and sex do not statistically correlate with either poor or excellent speech discrimination scores postcochlear implantation.
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      Otol Neurotol. 2007 Aug;28(5):615-28.Click here to read Links
      Ten-year follow-up of a consecutive series of children with multichannel cochlear implants.
      Uziel AS, Sillon M, Vieu A, Artieres F, Piron JP, Daures JP, Mondain M.

      Department of Otology and Neurotology, Montpellier University Hospital, Montpellier, France. alain.uziel@free.fr

      OBJECTIVES: To assess a group of children who consecutively received implants more than 10 years after implantation with regard to speech perception, speech intelligibility, receptive language level, and academic/occupational status. STUDY DESIGN: A prospective longitudinal study. SETTING: Pediatric referral center for cochlear implantation. PATIENTS: Eighty-two prelingually deafened children received the Nucleus multichannel cochlear implant. INTERVENTIONS: Cochlear implantation with Cochlear Nucleus CI22 implant. MAIN OUTCOME MEASURES: The main outcome measures were open-set Phonetically Balanced Kindergarten word test, discrimination of sentences in noise, connective discourse tracking (CDT) using voice and telephone, speech intelligibility rating (SIR), vocabulary knowledge measured using the Peabody Picture Vocabulary Test (Revised), academic performance on French language, foreign language, and mathematics, and academic/occupational status. RESULTS: After 10 years of implant experience, 79 children (96%) reported that they always wear the device; 79% (65 of 82 children) could use the telephone. The mean scores were 72% for the Phonetically Balanced Kindergarten word test, 44% for word recognition in noise, 55.3 words per minute for the CDT, and 33 words per minute for the CDT via telephone. Thirty-three children (40%) developed speech intelligible to the average listener (SIR 5), and 22 (27%) developed speech intelligible to a listener with little experience of deaf person's speech (SIR 4). The measures of vocabulary showed that most (76%) of children who received implants scored below the median value of their normally hearing peers. The age at implantation was the most important factor that may influence the postimplant outcomes. Regarding educational/vocational status, 6 subjects attend universities, 3 already have a professional activity, 14 are currently at high school level, 32 are at junior high school level, 6 additional children are enrolled in a special unit for children with disability, and 3 children are still attending elementary schools. Seventeen are in further noncompulsory education studying a range of subjects at vocational level. CONCLUSION: This long-term report shows that many profoundly hearing-impaired children using cochlear implants can develop functional levels of speech perception and production, attain age-appropriate oral language, develop competency level in a language other than their primary language, and achieve satisfactory academic performance.
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      Ear Hear. 2003 Feb;24(1 Suppl):2S-14S.Click here to read Links
      Background and educational characteristics of prelingually deaf children implanted by five years of age.
      Geers A, Brenner C.

      Central Institute for the Deaf, St Louis, Missouri, USA. ageers@earthlink.net

      PURPOSE: This study documents child, family and educational characteristics of a large representative sample of 8- to 9-yr-old prelingually deaf children who received a cochlear implant by 5 yr of age. Because pre-existing factors such as the child's gender, family characteristics, additional handicaps, age at onset of deafness and at implant, may affect postimplant outcomes, these variables must be accounted for before the impact of educational factors on performance with an implant can be adequately determined. Classroom variables that may affect postimplant outcomes include placement in public or private, mainstream or special education, oral or total communication environments. Other intervention variables include type and amount of individual therapy, experience of the therapist and parent participation in therapy. Documenting these characteristics for a large representative sample of implanted children can provide clinicians and researchers with insight regarding the types of families who sought early cochlear implantation for their children and the types of educational programs in which they placed their children after implantation. It is important to undertake studies that control for as many of these factors as possible so that the relative benefits of specific educational approaches for helping children to get the most benefit from their cochlear implant can be identified. METHOD: Over a 4-yr period, 181 children from across the US and Canada, accompanied by a parent, attended a cochlear implant research camp. Parents completed questionnaires in which they reported the child's medical and educational history, characteristics of the family, and their participation in the child's therapy. The parent listed names and addresses of clinicians who had provided individual speech/language therapy to the child and signed permission for these clinicians to complete questionnaires describing this therapy. RESULTS: To the extent that this sample is representative of those families seeking a cochlear implant for their child, especially during the initial period of device availability, this population can be characterized as follows. Most parents had normal hearing, were of majority (white) ethnicity and had more education and higher incomes than the general population. The families tended to be intact with both a mother and a father who involved their hearing-impaired child in family activities on a regular basis. The children were enrolled in the full range of educational placements available across the United States and Canada. Fairly even distributions of children from public and private schools, special education and mainstream classes and oral and total communication methodologies were represented. Educational placement changed as children gained increased experience with a cochlear implant. They received an increased emphasis on speech and auditory skills in their classroom settings and tended to move from private school and special education settings to public school and mainstream programs. These data support the position that early cochlear implantation is a cost effective procedure that allows deaf children to participate in a normal school environment with hearing age mates.
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      Ear Hear. 2003 Feb;24(1 Suppl):90S-105S.Click here to read Links
      Acoustic characteristics of the speech of young cochlear implant users: a comparison with normal-hearing age-mates.
      Uchanski RM, Geers AE.

      Central Institute for the Deaf, St Louis, Missouri 63110, USA. ruchanski@cid.wustl.edu

      OBJECTIVE: The primary objective of this study was to compare select acoustic characteristics of the speech of deaf children who use cochlear implants (young cochlear implant users) with those of children with normal hearing. A secondary objective of this study was to examine the effect, if any, of the deaf child's education (oral versus total communication) on the similarity of these acoustic characteristics to those of normal-hearing age-mates. DESIGN: Speech was recorded from 181 young cochlear implant users and from 24 children with normal hearing. All speech was produced by imitation, and consisted of complete sentences. Acoustic measures included voice onset time (/t/, /d/), second formant frequency (/i/, /[U0254]/), spectral moments (mean, skew and kurtosis of /s/ and /[U0283]/), a nasal manner metric, and durations (of vowels, words, and sentences). RESULTS AND DISCUSSION: A large percentage (46 to 97%) of the young cochlear implant users produced acoustic characteristics with values within the range found for children with normal hearing. Exceptions were sentence duration and vowel duration in sentence-initial words, for which only 23 and 25%, respectively, of the COCHLEAR IMPLANT users had values within the normal range. Additionally, for most of the acoustic measures, significantly more COCHLEAR IMPLANT users from oral than from total communication settings had values within the normal range. CONCLUSIONS: Compared with deaf children with hearing aids (from previous studies by others), deaf children who use cochlear implants have improved speech production skills, as reflected in the acoustic measures of this study. Placement in an oral communication educational setting is also associated with more speech production improvement than placement in a total communication setting.
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      Ear Hear. 2003 Feb;24(1 Suppl):69S-81S.Click here to read Links
      Personal, social, and family adjustment in school-aged children with a cochlear implant.
      Nicholas JG, Geers AE.

      Center for Applied Studies of Childhood Deafness and Adult Aural Rehabilitation, Central Institute for the Deaf, St Louis, Missouri 63110, USA. jnicholas@cid.wustl.edu

      OBJECTIVE: The present study sought to document the psycho-social adjustment of 181 school-aged deaf children who have had a cochlear implant for 4 or more yr and to examine parental satisfaction with the outcome of the implantation process on their child's life and on their family's life in general. DESIGN: Three measures were employed. One measure was a self-report instrument designed to assess perceived self-competence in children, one was a rating scale completed by parents that sought to assess the degree of their child's personal-social adjustment, and the third was a questionnaire given to parents on which they rated their satisfaction with aspects of the cochlear implant and how it had affected their child's functioning within the context of family life. RESULTS: Children generally perceived themselves (and parents perceived their children) as being competent and well adjusted in most aspects of daily life. Parents expressed a generally positive view of cochlear implantation and its effects on family life. None of the social-emotional adjustment measures was significantly related to the speech perception, speech production or language skills the child achieved postimplant. However, the parents' satisfaction with their child's cochlear implantation was significantly related to their child's speech and language achievements. On the perceived self-competence instrument, younger children and those with longer use of the updated SPEAK speech processor gave themselves higher ratings. Parent ratings of their child's adjustment tended to be higher for girls than for boys, for more rather than less intelligent children, and for children enrolled in private as opposed to public school settings. CONCLUSIONS: Deaf children who have used a cochlear implant for 4 to 6 yr report that they are coping successfully with the demands of their social and school environment, regardless of their speech and language achievements after implantation. Parents' ratings indicate that these children are emotionally and socially well adjusted and that they have benefited from cochlear implantation. To the extent that the children and their parents accurately reported their attitudes and feelings regarding their experiences at home and at school, these results represent an impressive level of personal and social adjustment when compared with previous literature on adjustment problems in deaf children. The extent to which these results are associated with cochlear implantation has not been determined and awaits comparative data from children without implants.

      Bilateral

      Acta Otolaryngol. 2007 Aug 22;:1-13 [Epub ahead of print]

      The benefits of sequential bilateral cochlear implantation for hearing-impaired children.
      Steffens T, Lesinski-Schiedat A, Strutz J, Aschendorff A, Klenzner T, Rühl S, Voss B, Wesarg T, Laszig R, Lenarz T.
      HNO Klinik Universitätsklinikum Regensburg, Germany.
      Conclusion. Sequential bilateral implantation offers listening advantages demonstrable on speech recognition in noise and for lateralization. Whilst the trend was for shorter inter-implant intervals and longer implant experience to positively impact binaural advantage, we observed no contraindications for binaural advantage. Objective. To evaluate the benefits of sequential bilateral cochlear implantation over unilateral implantation in a multicentre study evaluating speech recognition in noise and lateralization of sound. Subjects and methods. Twenty children, implanted bilaterally in sequential procedures, had the following characteristics: they were native German-speaking, were3 years or older and had a minimum of 1 year inter-implant interval and had between 2 months and 4 years 7 months binaural listening experience. Binaural advantage was assessed including speech recognition in noise using the Regensburg modification of the Oldenburger Kinder-Reimtest (OLKI) and lateralization of broadband stimuli from three speakers. Results. A significant binaural advantage of 37% was observed for speech recognition in noise. Binaural lateralization ability was statistically superior for the first and second implanted ear (p=0.009, p=0.001, respectively). Binaural experience was shown to correlate moderately with absolute binaural speech recognition scores, with binaural advantage for speech recognition and with binaural lateralization ability. The time interval between implants correlated in an inverse direction with binaural advantage for speech recognition.

      Arch Otolaryngol Head Neck Surg. 2006 Oct;132(10):1133-6.Click here to read Links
      Central auditory development in children with bilateral cochlear implants.
      Bauer PW, Sharma A, Martin K, Dorman M.

      Department of Otolaryngology, University of Texas Southwestern Medical Center, Dallas 75230, USA. bauer@entforchildren.net

      OBJECTIVE: To examine the time course of maturation of P1 latencies in infant sequential and simultaneous bilateral cochlear implant recipients. DESIGN: Retrospective case series. SETTING: Pediatric collaborative cochlear implant program. PATIENTS: Four children who received bilateral cochlear implants prior to age 2 years. INTERVENTION: Cortical auditory evoked potential was completed to determine the latency of the P1 response in 4 children with bilateral cochlear implants. MAIN OUTCOME MEASURES: Longitudinal development of the latency of the P1 cortical auditory evoked potential in children who received bilateral cochlear implants prior to age 2 years. RESULTS: In 2 patients who received sequential bilateral implants, P1 latencies recorded from the first implanted ear were within normal limits after 3 to 6 months of implant use. By comparison, P1 latencies from the second implanted ear reached normal limits as early as 1 month after implant use. In 2 patients who received simultaneous bilateral implants, P1 latencies from both ears were also within normal limits in a very short time frame (ie, by 1 month poststimulation). CONCLUSIONS: Our data suggest a high degree of plasticity of the central auditory pathways after early bilateral implantation. We find that P1 latencies provide a clinically useful biomarker of central auditory system development in children after cochlear implantation.
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      Otol Neurotol. 2007 Aug;28(5):589-596.Click here to read Links
      1-Year Postactivation Results for Sequentially Implanted Bilateral Cochlear Implant Users.
      Wolfe J, Baker S, Caraway T, Kasulis H, Mears A, Smith J, Swim L, Wood M.

      *Hearts for Hearing, †Otologic Medical Clinic at the Hough Ear Institute, and ‡INTEGRIS Health Decision Support Services, Oklahoma City, Oklahoma, U.S.A.

      OBJECTIVE:: Evaluate speech recognition in quiet and in noise for a group of 12 children, all of whom underwent sequential bilateral cochlear implantation at various ages (range, 1 yr, 8 mo to 9 yr, 6 mo at time of second implant). STUDY DESIGN:: Retrospective. SETTING:: Outpatient cochlear implant clinic. PATIENTS:: Children who underwent sequential bilateral cochlear implantation. INTERVENTION:: Rehabilitative. MAIN OUTCOME MEASURES:: Speech recognition in quiet was evaluated for each ear separately using single-word speech recognition assessments (Multisyllabic Lexical Neighborhood Test and Early Speech Perception Test) via recorded presentation. Speech recognition in noise was assessed for each ear separately and in the bilateral condition by obtaining a spondee recognition threshold in the presence of speech-weighted noise presented at 45 dB hearing level. The primary outcome measure for speech recognition in noise assessment was the signal-to-noise ratio for 50% performance, which was calculated by determining the difference between the presentation level of the noise and the presentation level at which the speech recognition threshold was obtained. The results of these assessments were contrasted between children receiving their second cochlear implant before 4 years of age and children receiving their second cochlear implant after 4 years of age. RESULTS:: A statistically significant difference for speech recognition scores in quiet was obtained between the early-implanted ear and the late-implanted ears for children receiving their second cochlear implant after 4 years of age. There was not a statistically significant difference in speech recognition scores in quiet between the early-implanted and late-implanted ears of children receiving their second cochlear before 4 years of age. Both groups of children possessed better speech recognition scores in noise (statistically significant at an alpha = 0.05) in the bilateral condition relative to either unilateral condition. However, there was not a statistically significant relationship between speech recognition performance in noise and the duration of deafness of the later implanted ear. CONCLUSION:: Bilateral cochlear implantation allowed for better speech recognition in noise relative to unilateral performance for a group of 12 children who underwent sequential bilateral cochlear implantation at various ages. There was not a statistically significant relationship between speech recognition in noise benefit, which was defined as the difference in performance between the first implanted ear and the bilateral condition and the age at which the second implant was received. Children receiving bilateral cochlear implants younger than 4 years of age achieved better speech recognition in quiet performance for the later implanted ear as compared with children receiving their second cochlear implant after 4 year of age.

      Otol Neurotol. 2007 Aug;28(5):649-57.Click here to read Links
      Importance of age and postimplantation experience on speech perception measures in children with sequential bilateral cochlear implants.
      Peters BR, Litovsky R, Parkinson A, Lake J.

      Dallas Otolaryngology Cochlear Implant Program, Dallas, TX 75230, USA. drpeters@dallasoto.com

      OBJECTIVES: Clinical trials in which children received bilateral cochlear implants in sequential operations were conducted to analyze the extent to which bilateral implantation offers benefits on a number of measures. The present investigation was particularly focused on measuring the effects of age at implantation and experience after activation of the second implant on speech perception performance. STUDY DESIGN: Thirty children aged 3 to 13 years were recipients of 2 cochlear implants, received in sequential operations, a minimum of 6 months apart. All children received their first implant before 5 years of age and had acquired speech perception capabilities with the first device. They were divided into 3 age groups on the basis of age at time of second ear implantation: Group I, 3 to 5 years; Group II, 5.1 to 8 years; and Group III, 8.1 to 13 years. Speech perception measures in quiet included the Multisyllabic Lexical Neighborhood Test (MLNT) for Group I, the Lexical Neighborhood Test (LNT) for Groups II and III, and the Hearing In Noise Test for Children (HINT-C) sentences in quiet for Group III. Speech perception in noise was assessed using the Children's Realistic Intelligibility and Speech Perception (CRISP) test. Testing was performed preoperatively and again postactivation of the second implant at 3, 6, and 12 months (CRISP at 3 and 9 mo) in both the unilateral and bilateral conditions in a repeated-measures study design. Two-way repeated-measures analysis of variance was used to analyze statistical significance among device configurations and performance over time. SETTING: US Multicenter. RESULTS: Results for speech perception in quiet show that children implanted sequentially acquire open-set speech perception in the second ear relatively quickly (within 6 mo). However, children younger than 8 years do so more rapidly and to a higher level of speech perception ability at 12 months than older children (mean second ear MLNT/LNT scores at 12 months: Group I, 83.9%; range, 71-96%; Group II, 59.5%; range, 40-88%; Group III, 32%; range, 12-56%). The second-ear mean HINT-C score for Group III children remained far less than that of the first ear even after 12 months of device use (44 versus 89%; t, 6.48; p<0.001; critical value, 0.025). Speech intelligibility for spondees in noise was significantly better under bilateral conditions than with either ear alone when all children were analyzed as a single group and for Group III children. At the 9-month test interval, performance in the bilateral configuration was significantly better for all noise conditions (13.2% better for noise at first cochlear implant, 6.8% better for the noise front and noise at second cochlear implant conditions, t=2.32, p=0.024, critical level=0.05 for noise front; t=3.75, p<0.0001, critical level=0.05 for noise at first implant; t=2.73, p = 0.008, critical level=0.05 for noise at second implant side). The bilateral benefit in noise increased with time from 3 to 9 months after activation of the second implant. This bilateral advantage is greatest when noise is directed toward the first implanted ear, indicating that the head shadow effect is the most effective binaural mechanism. The bilateral condition produced small improvements in speech perception in quiet and for individual Group I and Group II patient results in noise that, in view of the relatively small number of subjects tested, do not reach statistical significance. CONCLUSION: Sequential bilateral cochlear implantation in children of diverse ages has the potential to improve speech perception abilities in the second implanted ear and to provide access to the use of binaural mechanisms such as the head shadow effect. The improvement unfolds over time and continues to grow during the 6 to 12 months after activation of the second implant. Younger children in this study achieved higher open-set speech perception scores in the second ear, but older children still demonstrate bilateral benefit in noise. Determining the long-term impact and cost-effectiveness that results from such potential capabilities in bilaterally implanted children requires additional study with larger groups of subjects and more prolonged monitoring.

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      Rationale for Bilateral bibliography:
      http://cochlearimplants.dallasoto.com/facts/Rationale%20for%20Bilateral%20Cochlear%20Implantation%20Final.pdf.

      Meningitis

      Otolaryngol Head Neck Surg. 2007 Apr;136(4):589-96.Click here to read Click here to read Links
      Threshold shift: effects of cochlear implantation on the risk of pneumococcal meningitis.
      Wei BP, Shepherd RK, Robins-Browne RM, Clark GM, O'Leary SJ.

      Bionic Ear Institute, the University of Melbourne, Melbourne, Victoria, Australia. bwei@bionicear.org

      OBJECTIVES: The study goals were to examine whether cochlear implantation increases the risk of meningitis in the absence of other risk factors and to understand the pathogenesis of pneumococcal meningitis post cochlear implantation. STUDY DESIGN AND SETTING: Four weeks following surgery, 54 rats (18 of which received a cochleostomy alone, 18 of which received a cochleostomy and acute cochlear implantation using standard surgical techniques, and 18 of which received a cochlear implant) were infected with Streptococcus pneumoniae via three different routes of bacterial inoculation (middle ear, inner ear, and intraperitoneal) to represent all potential routes of bacterial infection from the upper respiratory tract to the meninges. RESULTS: The presence of a cochlear implant reduced the threshold of bacteria required to cause pneumococcal meningitis from all routes of infection in healthy animals. CONCLUSION: The presence of a cochlear implant increases the risk of pneumococcal meningitis regardless of the route of bacterial infection. SIGNIFICANCE: Early detection and treatment of pneumococcal infection such as otitis media may be required, as cochlear implantation may lead to a reduction of infectious threshold for meningitis.
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